Re: template problem: local variable as non-type argument

Anthony Williams <>
Fri, 6 Feb 2009 12:33:18 CST
vl106 <> writes:

I have to better describe the problem:

[kind of pseudo code]
void receive_message(int messageId, char* data) {
    Base& new_message = Factory::createMessage(messageId, data); //
transition to C++

From old, non-C++ library I receive messages identified by int id.

I want to map this "event" into an "object-oriented" message. Further
receive_message should stay stable. That is when a new kind of message
is received I only want to create a new specialization
This specialization will have a process method with different

Why do you need a specialization? Why can't you just define a normal
class derived from Base? Once you're out of createMessage you can't
access the derived class anyway unless you know what it is.

I would just have createMessage do a lookup of ID to class to create,
either using a switch statement or a lookup table.

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